USED REFLOW OVENS DRIVERS
USED REFLOW OVENS CRACK

USED REFLOW OVENS DRIVERS

Thermal history variation within printed circuit assemblies (PCAs) during reflow soldering is considered one of the main drivers for manufacturing defects. Furthermore, findings in this study were compared with those in previous studies, and the comparison proved the validity of this study. However, these compounds did not affect the reliability of the solder joints. The intermetallics growth was about 10% after 3000 thermal cycles. The intermetallic thicknesses were less than 3 μm. A crystalline star-shaped structure of Sn–Ni–Cu–P was also observed in a solder joint. The solder joints consisted of two Ag–Sn compounds exhibiting unique structures of Sn-rich and Ag-rich compounds. In addition, the intermetallic interfaces were found to have Sn–Ni–Cu. Failures were not found before 5700 thermal cycles and the characteristic lives of all solder joints produced using different process and design parameters were more than 7200 thermal cycles, indicating robust solder joints produced with a wide process window. Microstructure analysis and measurements of interface intermetallic growth were conducted using samples after 0, 1000, 20 thermal cycles.

USED REFLOW OVENS CRACK

The assembled boards were subjected to the thermal cycling test (−40 ☌/+125 ☌), and crack initiation and crack propagation during the test were studied. Lead-free SnAgCu plastic-ball-grid-array (PBGA) components were assembled onto PCBs using SnAgCu solder paste. Lead-free printed-circuit-board (PCB) assemblies were carried out using different foot print designs on PCBs, solder paste deposition volume and reflow profiles. Failure modes of solder joints were analyzed to determine the effects of process conditions on crack propagation. In this study, microstructure evolution at intermetallic interfaces in SnAgCu solder joints of an area array component was investigated at various stages of a thermal cycling test.

Used reflow ovens